morgan/systemd
1
0
Fork 0
mirror of https://github.com/morgan9e/systemd synced 2026-04-14 00:14:32 +09:00
Code Issues Packages Projects Releases Wiki Activity

btrfs-util: try unlinkat(AT_REMOVEDIR) before resorting to btrfs ioctls

Browse Source 
An empty btrfs subvolume can always be removed without privs, hence try
to use unlinkat() first.
This commit is contained in:
Lennart Poettering
2025-07-15 18:29:03 +02:00
parent 07345762c8
commit 265b3fbd52
1 changed files with 9 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/shared/btrfs-util.c
View File

@@ -907,6 +907,11 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
if (r == 0) /* Not a btrfs subvolume */
return -ENOTTY;
/* Before we try anything, let's see if 'user_subvol_rm_allowed' is enabled and we can just remove
* the dir directly */
if (unlinkat(fd, subvolume, AT_REMOVEDIR) >= 0)
goto finish;
if (subvol_id == 0) {
r = btrfs_subvol_get_id_fd(subvol_fd, &subvol_id);
if (r < 0)
@@ -916,10 +921,8 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
/* First, try to remove the subvolume. If it happens to be
* already empty, this will just work. */
strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1);
if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) >= 0) {
(void) btrfs_qgroup_destroy_recursive(fd, subvol_id); /* for the leaf subvolumes, the qgroup id is identical to the subvol id */
return 0;
}
if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) >= 0)
goto finish;
if (!(flags & BTRFS_REMOVE_RECURSIVE) || errno != ENOTEMPTY)
return -errno;
@@ -1001,6 +1004,8 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) < 0)
return -errno;
finish:
/* for the leaf subvolumes, the qgroup id is identical to the subvol id */
(void) btrfs_qgroup_destroy_recursive(fd, subvol_id);
return 0;
}